i do not see where MC-HL is approved for use in underground wiring of fuel dispensing facilities in 514.8. MI cable, yes. not MC. is this cable dual rated?
Agreed. You can't run it underground, and there's no sense switching to it above the seal off where the conduit emerges from below grade (raceway, wiring entering a class 1 div 2 location needs to be sealed, iirc) because there isn't any room. You could switch after emerging from below ground, but it's not worth it.
Dispenser pans and under dispensers, be they Wayne or Gilbarco, are super tight. There are 1 or 2 filters depending on whether its gas, diesel, or both, and you have the piping from the pump sump. Rigid with capped elbows, an assortment of nipples, unions, etc. It wouldn't surprise me if it was cheaper to pipe it in rigid to the dispenser than buying 1 sealing connector for MC-HL. Once you get the hang of it it goes pretty quick, and hopefully the engineer designed it so you poke up next to the dispenser pan on the opposite side from the filters. That way you can skip installing the stupid fiberglass or plastic seals around the conduit.
Some day I'm going to get my hands on some MC-HL.
As Master Nater stated: MI cable seems to be the only thing allowed for underground installation in accordance with 514.8 (2023 NEC). MC cable can only be used if ABOVE a classified space in accordance with 514.7. And the underground MI cable would be for both the 240 AND the 120 controls (according to Article 332 Part 2).
But it also states that rigid metal, PVC, RTRC, & HDPE conduits can be used. Does that mean the MI cable has to be run inside of conduit as well?
No, it doesn't, because it's listed as a separate approved wiring method for underground. That's why its 514.8(B), while metal conduit is (A) and Non-metallic conduit is (C). I don't know why anyone would bother running it, since rigid stubs and connecting the dots with PVC is pretty easy.
